Ag@CuO@Cu(OH) 2 : A Synergistic Catalyst for H 2 O 2 Detection with Peroxidase‐Mimic Activity without Interference of O 2

Herein, we present silver nanoparticle anchored on copper oxide and copper hydroxide (Ag@CuO@Cu(OH) 2 ) by green synthetic approach. Interestingly, as‐obtained Ag@CuO@Cu(OH) 2 not only enhances the peroxidase‐like activity but also eliminates oxidase‐like activity. The peroxidase‐like activity was enhanced mainly due to the abundance of Ag + and Cu 2+ vacant states, which populate reactive oxygen species (ROS). This prolonged peroxidase‐like activity of Ag@CuO@Cu(OH) 2 was successfully recognized H 2 O 2 and also have long stability and repeatability. The proposed strategy, finding nanozymes with single activity will open a new opportunity to enhance the performance of colorimetric sensors.